1. Field of the Invention
This invention relates to hydrocarbon fuels and more particularly to fuels comprising a mixture of hydrocarbons in the gasoline boiling range and acyl glycine oxazolines acting as detergents therein.
As is well known hydrocarbon fuels have a tendency to form polymeric materials (variously called "gum" or "sludge" or "varnish") in various parts of fuel systems. These resin-like deposits tend to form in the fuel supply lines, fuel filter, carburetor, fuel control injectors, intake manifold and valve stems. Such deposits are objectionable not only because of their effect on mechanical performance but also because they decrease the breathing efficiency in engines of the spark ignition type.
Although each type of fuel is composed essentially of hydrocarbons their stability characteristics differ considerably. Thus typical automotive fuels contain straight and branched chains compounds while aircraft fuels contain a smaller proportion of olefins. Currently, certain types of fuels contain increased amounts of cracked stocks resulting in a higher olefin content and an increased susceptibility to the formation of gum.
For obvious reason, it is advantageous to use an additive which provides detergency property to the fuel.
2. Description of Prior Disclosures
Coassigned U.S. Pat. No. 3,773,479 describes a motor fuel composition comprising a mixture of hydrocarbons in the gasoline boiling range containing a minor amount of a substituted asparagine having the formula: ##STR2## in which R and R' each represent a secondary or tertiary alkyl or alkylene radical having from about seven to about 20 carbon atoms. Coassigned U.S. Pat. No. 4,052,322 describes lubricating greases corrosion-inhibited by N-acyl sarcosines and sodium nitrite. Related subject matter is disclosed also in an article by Pine and Spivack in the publication "Corrosion," vol. 13, N.92 (1957) and in German Pat. No. 1,094,038.